Therapeutic ultrasound apparatus and method

ABSTRACT

Various devices related to a therapeutic ultrasound device for use during a medical procedure to cauterize tissue are disclosed. The therapeutic ultrasound device can include an inner tube assembly and an outer tube assembly. The device can further include a tissue engagement assembly that is secured to the distal end of the inner tube and the distal end of the outer tube. The tissue engagement assembly includes a plurality of transducers configured to provide therapeutic ultrasound. The device can include a housing assembly that is secured to the proximal end of the inner tube and the proximal end of the outer tube. The housing assembly can include a handle configured to actuate the inner tube relative to the outer tube to engage and disengage the tissue engagement assembly.

PRIORITY STATEMENT

This application claims a priority benefit under 35 U.S.C. § 119 of U.S.Patent Application No. 62/560,069, filed Sep. 18, 2017, the entirety ofwhich is hereby incorporated by reference herein.

BACKGROUND

This disclosure relates to methods and apparatus for surgical proceduresthat utilize therapeutic ultrasound. Therapeutic ultrasound refers tothe use of ultrasonic waves to induce changes in tissue state throughboth thermal effects (e.g., induced hyperthermia) and mechanical effects(e.g., induced cavitation). Therapeutic ultrasound can refer to eitherHigh Intensity Focused Ultrasound (HIFU) or Direct TherapeuticUltrasound (DTU) and can be employed in both hyper-thermic andcavitational medical applications, whereas low intensity ultrasound hasbeen used principally for its cavitation effect. Diagnostic medicalultrasonic imaging is well known, for example, in the common use ofsonograms for fetal examination.

BRIEF DESCRIPTION OF THE FIGURES

Various embodiments are depicted in the accompanying drawings forillustrative purposes, and should not be interpreted as limiting thescope of the embodiments. Furthermore, various features of differentdisclosed embodiments can be combined to form additional embodiments,which are part of this disclosure.

FIG. 1A illustrates an exploded view of a sample therapeutic ultrasounddevice.

FIG. 1B illustrates a cross-sectional side view of the sampletherapeutic ultrasound device of FIG. 1A.

FIG. 1C illustrates a side view of internal elements of the sampletherapeutic ultrasound device of FIG. 1A wherein the external housing isremoved.

FIG. 1D illustrates an exploded view of the internal elements shown inFIG. 1C, namely, an outer tube assembly and an inner tube assembly, ofthe sample therapeutic ultrasound device of FIG. 1A.

FIG. 2A illustrates an exploded view of the outer tube assembly of thesample therapeutic ultrasound device of FIG. 1A.

FIGS. 2B-2C illustrate a plurality of views of a distal end of the outertube assembly of the sample therapeutic ultrasound device of FIG. 1A.

FIG. 2D illustrates a cross-sectional view of a proximal end of theouter tube assembly of the sample therapeutic ultrasound device of FIG.1A.

FIGS. 2E-2H illustrate a plurality of views of an adaptor of the outertube assembly of the sample therapeutic ultrasound device of FIG. 1A.

FIG. 3A illustrates an exploded view of the inner tube assembly of thesample therapeutic ultrasound device of FIG. 1A.

FIGS. 3B and 3C illustrate a plurality of views of the inner tubeassembly of the sample therapeutic ultrasound device of FIG. 1A.

FIG. 3D illustrates a cross-section of an engagement of variouscomponents of the inner tube assembly of the sample therapeuticultrasound device of FIG. 1A.

FIGS. 4A-4F illustrate various views of a tissue engagement assemblylocated on a distal end of the sample therapeutic ultrasound device ofFIG. 1A.

FIG. 5A illustrates an exploded view of the tissue engagement assemblylocated at the distal end of the sample therapeutic ultrasound device ofFIG. 1A.

FIG. 5B illustrates a prospective view of the tissue engagement assemblylocated at the distal end of the sample therapeutic ultrasound device ofFIG. 1A.

FIGS. 5C-5D illustrate cross-sectional views of the tissue engagementassembly located at the distal end of the sample therapeutic ultrasounddevice of FIG. 1A.

FIG. 5E illustrates a cross-sectional view of the distal end of thesample therapeutic ultrasound device of FIG. 1A located along plane“5E-5E” as shown in FIG. 5B.

FIG. 5F illustrates a cross-sectional view of the distal end of thesample therapeutic ultrasound device of FIG. 1A located along plane“5F-5F” as shown in FIG. 5B.

FIGS. 6A-6B illustrate a first embodiment of an acoustic stack locatedin the tissue engagement assembly of the sample therapeutic ultrasounddevice of FIG. 1A.

FIG. 6C illustrates an exploded view of a first embodiment of theacoustic stack of FIGS. 6A-6B.

FIGS. 7A-7B illustrate a second embodiment of the acoustic stack locatedin the tissue engagement assembly of the sample therapeutic ultrasounddevice of FIG. 1A.

FIG. 7C illustrates an exploded view of a second embodiment of theacoustic stack of FIGS. 7A-7B.

FIGS. 8A-8B illustrate a third embodiment of the acoustic stack locatedin the tissue engagement assembly of the sample therapeutic ultrasounddevice of FIG. 1A.

FIG. 8C illustrates an exploded view of the third embodiment of theacoustic stack of FIGS. 8A-8B.

FIG. 9A illustrates a cross-sectional view of an embodiment of atransducer formed from one of the jaws of the tissue engagement assemblyof the sample therapeutic ultrasound device of FIG. 1A, and configuredto receive any of the disclosed acoustic stacks illustrated in FIGS.6A-6B, 7A-7B, and 8A-8B.

FIG. 9B illustrates a cross-sectional view of another embodiment of atransducer formed from one of the jaws of the tissue engagement assemblyof the sample therapeutic ultrasound device of FIG. 1A, and configuredto receive any of the disclosed acoustic stacks illustrated in FIGS.6A-6B, 7A-7B, and 8A-8B.

FIG. 10 illustrates the relationship between jaw clamp force over arange of jaw opening angles for straight and curved slots in the ears ofthe pair of jaws.

FIG. 11 illustrates the relationship between the velocity of sound intissue and temperature.

FIG. 12A illustrates the relationship between the maximum temperatureand acoustic energy with time fixed.

FIG. 12B illustrates the relationship between maximum temperature andtime with power and intensity fixed.

FIG. 12C illustrates the relationship between the maximum temperatureand intensity with time fixed.

FIG. 12D illustrates the time required to reach a given temperature at aspecific power.

FIG. 13A-13D illustrate the use of the voltage standing wave ratio todetermine end of treatment.

FIG. 14 illustrates an example of the relationship between energy andclamping force as it relates to sealing and dividing tissue.

DETAILED DESCRIPTION

Various therapeutic ultrasound apparatus and methods are disclosed thatmay be employed to achieve one or more desired improvements in the fieldof surgery. For purposes of presentation, certain embodiments aredisclosed with respect to a surgical therapeutic ultrasound apparatusand methods of use, but the disclosed embodiments can be used in othercontexts as well. Indeed, the described embodiments are examples onlyand are not intended to restrict the general disclosure presented andthe various aspects and features of this disclosure. The generalprinciples described herein may be applied to embodiments andapplications other than those discussed herein without departing fromthe spirit and scope of the disclosure. This disclosure should beaccorded the widest scope consistent with the principles and featuresthat are disclosed or suggested herein.

Although certain aspects, advantages, and features are described herein,it is not necessary that any particular embodiment include or achieveany or all of those aspects, advantages, and features. For example, someembodiments may not achieve the advantages described herein, but mayachieve other advantages instead. No feature, component, or step isnecessary or critical.

Overview

In the U.S. alone, several hundred thousand surgical procedures areperformed each year that involve the removal of tissue, or a portion ofan organ because of some pathology involving the tissue. Many of theseprocedures remove benign or malignant tumors. Although a significantpercentage of such tissue and organ removal procedures employconventional surgical techniques, a major effort has been directed toreplacing conventional surgical techniques with minimally invasivesurgical techniques to reduce morbidity. However, performing suchsurgery using minimally invasive instruments requires significanttraining and advanced skills on the part of the operating physician.Disclosed below are methods and apparatus that are minimally invasiveand are easier to implement than those currently used.

During invasive surgery, an obvious problem is bleeding. In aretrospective cohort study involving 600 hospitals, bleedingcomplications occurred in approximately 45% of surgical procedures,increasing hospitalization by about 125% (7 days on average), andincreasing hospital costs by ˜$7,500 per patient (per procedure).Bleeding also significantly contributes to the majority of theapproximately 120,000 trauma deaths per year. In trauma, 30% to 40% ofdeaths are related to uncontrolled bleeding. Blood transfusions (plannedor unexpected) and reoperations are used to mitigate bleeding and avertdeath. These procedures can be costly and are associated withcomplications. Blood transfusion can lead to nosocomial infection,immunosuppression, transfusion-related acute lung injury, and evendeath. Reoperations lead to increased costs and longer hospitalization.As a result, many needless bleeding complications occur with currenttechnologies resulting in increased hospitalization times, hospitalcosts, and patient deaths. To reduce bleeding, surgical techniques areneeded to provide for fast and robust control of bleeding—allowingsurgical procedures without hemorrhaging as well as rapidly controllingbleeding in trauma.

The most common surgical technique in the state of the art forcoagulating bleeding vessels is to apply an electrical cauterizing probeto the bleeding site. However, if a bleeding vessel is more than about1.5 millimeters (mm) in diameter, or an organ which is highlyvascularized and where uncontrolled hemorrhage is the primary cause ofdeath, direct electrical cauterization is ineffective. In suchinstances, a more complicated technique of clamping of a large bloodvessel and electrical cauterization via the clamp or with laser lightcan instead be used. However, problem frequently faced, that is notsolved with either electrical or laser cauterization techniques, is thecontrol of a rapidly bleeding vessel because the blood egress is oftensufficiently large enough to carry the heat away before coagulation ortissue necrosis is accomplished. Particularly in surgery involvingorgans, neither electrical or laser cauterization is effective.Moreover, organs such as the liver and the spleen are subject tobleeding profusely from cracks in the parenchyma, which is usuallydiffuse and non-pulsatile due to the large number of small vessels.

The disclosed methods and apparatus can be used to assist emergency,specialty, and general physicians in performing surgeries rapidly andwithout common complications associated with bleeding. This can reducesurgical and anesthesia time and minimizes blood product usage, whichcan improve patient outcomes and decrease healthcare costs.

Therapeutic Ultrasound Overview

In view of the surgical procedures described above, disclosed aremethods and apparatus for enabling surgical procedures relating tobloodless surgery and for stemming hemorrhaging. For example,therapeutic ultrasound can be used to form cauterized tissue regionsprior to surgical incision. This can be particularly effective for usein surgical lesion removal or resecting highly vascularized tissue.

Generally, therapeutic ultrasound is a modality in interventionalmedicine that is based on the delivery of acoustic energy at ultrasonicfrequencies within the human body with the precise intent of elicitingwell defined biological effects. These biological consequences areinduced, or mediated, primarily by two mechanisms of action: thermaleffects and mechanical effects. Thermal effects derive from theabsorption of the vibrational acoustic energy by the tissue (throughrelaxation and thermos-viscous processes) and its conversion into heatwhich, in turn, generates a temperature increase in the exposed region.Mechanical effects are due to the large gradients in pressure associatedwith the oscillatory nature of the ultrasound waves which produce highstress and strain forces as experienced by the medium. Additionally, inthe presence of gas bodies within the ultrasonic field of action,cavitation may also occur. Cavitation is the dynamic activity of gasbubbles which grow and collapse under the influence of an acousticfield. It can be stable and sustained, when the bubbles oscillate inphase with the acoustic wave without being destroyed, in which case theyproduce significant shearing forces and additional viscous heating; orit can be inertial and transient, when new gas bubbles are nucleatedfrom dissolved gas in the tissue and they rapidly grow and violentlycollapse before dissolving again, in which case they produce extremelyhigh mechanical stresses, shock waves, and strong fluid microjets.

One type of therapeutic ultrasound is High Intensity TherapeuticUltrasound (also commonly referred to as HIFU-High Intensity FocusedUltrasound and FUS-Focused Ultrasound Surgery). HIFU is mainly directedtowards the very rapid heating of tissue above the proteindenaturization and cell coagulative necrosis thresholds and is intendedto create a permanent, irreversible, and localized thermal lesion withinthe tissue or to cauterize a bleeding vessel. This results in theconcentration of the majority of the available input power in a focalvolume of the order of 1-2 wavelengths in cross section and about 5-7wavelengths in length (approximately 1.5×1.5×10 mm3 for a 1 MHz system)with extremely high energy densities in the order of hundreds tothousands of Watts/cm². This high-energy concentration allows for rapidtemperature rise in the focal volume such that cell necrosis andablation is achieved within 1-2 seconds. Although energy densities atthe face of the ultrasound applicator are orders of magnitude lower thanat the focus, because of the multiple unit lesions necessary for a fulltreatment, the ultrasound energy deposition at the skin interface andimmediately below compounds during the whole application and typicallyunwanted skin burns and subcutaneous damage occur.

HIFU can be employed in both hyperthermic and cavitational medicalapplications. HIFU waves, for example, can be propagated into tissuetoward a discrete focal region, and the accumulation of the resultantharmonic frequencies can induce rapid heating at the focal region thatablates, necrotizes, and/or otherwise damages the tissue. In a clinicalsetting, HIFU-induced heating can be used to treat benign and malignanttumors (e.g., in the brain, uterus, prostate, liver, etc.) and/orocclude blood vessels (e.g., to induce hemostasis of internal bleeds,intervene in fetal blood sharing anomalies, and confine tumor bloodsupply). During HIFU therapy and/or other treatments that formheat-induced lesions, image guidance and treatment monitoring (e.g.,temperature monitoring) can be used for controlling and optimizing theparameters of the treatment and assessing its efficacy.

In HIFU hyperthermia treatments, the intensity of ultrasonic wavesgenerated by a highly focused transducer increases from the source tothe region of focus where it can reach a very high temperature, (e.g.,98° Centigrade). The absorption of the ultrasonic energy at the focuscan induce a sudden temperature rise of tissue which can be as high asbetween 100-200° K/sec. Such a dramatic increase in temperature cancause the ablation of target cells at the focal region. The focal regiondimensions are referred to as the depth of field, and the distance fromthe transducer to the center point of the focal region is referred to asthe “depth of focus.”

Thus, HIFU hyperthermia treatments can result in necrotization of aninternal lesion without damage to the intermediate tissues. Thedisclosed methods and apparatus using HIFU are a non-invasive surgicaltechnique because the ultrasonic waves provide a non-effectivepenetration of intervening tissues, yet with sufficiently lowattenuation configured to deliver energy to a small focal target volume.For example, a very high frequency, e.g., 30 MHz wave would be absorbednearly immediately by the first tissue it is applied to. Yet, lowerfrequencies, e.g., 30 KHz-60 KHz, are associated with cavitation effectsbecause of the longer rarefaction time periods, allowing gaseous vaporformation. Thus, the effect of ultrasound energy is quite different at afrequency of 30 KHz versus 30 MHz. Moreover, the rate of heat generationin tissue is proportional to the absorption constant. For example, forthe liver, the attenuation constant is approximately 0.0015 at 30 KHz,but is approximately 0.29 at 3 MHz. Therefore, all other variables beingequal, the heat generated in liver tissue is about 190 times greater at3 MHz than at 30 KHz. While this means hyperthermia can be achieved morequickly and to a much greater level with high frequencies, the danger tointervening tissue between the transducer and the focal region is muchmore prevalent. Therefore, by instead using a lower frequency, energycan be delivered to a small focused target volume of tissue withoutdamaging intervening tissues.

Direct Therapeutic Ultrasound (DTU), another type of therapeuticultrasound, refers to the use of direct therapeutic ultrasonic waves toinduce changes in tissue state through both thermal effects (e.g.,induced hyperthermia) and mechanical effects (e.g., induced cavitation).DTU can be used to directly lock and compress vascularized tissue, up toseveral millimeters thick, before being coagulated and sealed by theultrasound energy in seconds. While still based on ultrasonicallymediated thermal mechanisms, in contrast to traditional high intensitytherapeutic ultrasound, this approach utilized significantly lower powerdensities (in the order of 5-30 W/cm²) and a uniform distribution of theultrasound energy throughout the full treatment domain, thus avoidinggeneration of localized hot spots and collateral damage. In fact, thetreatment region is fully contained and well-defined within the oppositejaws of the device where a uniform planar standing wave is generatedbetween the two opposing ultrasound transducers, quickly dissipatingaway from the applicators edges resulting in minimal thermal spreading.

This type of application is intended for open and minimally-invasivelaparoscopic surgery, and compared to standard HIFU applications doesnot require additional targeting and monitoring systems and does notsuffer from similar safety concerns in terms of on-path unintendedinjury and/or cavitation effects. This is due to the fact that thepropagation path is only few millimeters long and fully restrictedwithin the applicator footprint thus avoiding significant energydiffraction; peak rarefactional pressure are well below the in-vivothreshold for cavitation processes; and the tissue is subject tosignificant overpressure from the clamping device, additionallyinhibiting the inception of bubble formation and cavitation.

Disclosed is also an apparatus configured to emit therapeutic ultrasound(whether HIFU or DTU) from one or more transducers that are attached toa minimally invasive surgical instrument. Such a tool can providesufficient clamping or engagement pressure to collapse blood vessels'walls, so that they will be sealed by the application of the DTU, and bythe resulting thermal ablation and tissue cauterization. Such aninstrument can provide feedback to the user that the lesion iscompletely transmural and that blood flow to the region distal of theline of thermal ablation has ceased. In some embodiments, instrumentshaving opposed arms can be configured for use in conventional surgicalapplications. Instruments can be implemented with transducers on onlyone arm, and an ultrasound reflective material disposed on the otherarm.

The disclosure provided herein describes apparatus and methods relatedto performing surgical procedures with a minimum of bleeding. In someembodiments, such procedures are minimally invasive procedures (e.g.,laparoscopy, endoscopy, etc.). In other embodiments the disclosedprocedures and apparatus can also be applied to more invasive surgicalprocedures. The disclosed apparatus and methods can enable removal ofundesirable tissues, such as benign and malignant tumors, from the bodywithout fear of uncontrolled bleeding that can result from suchprocedures using conventional techniques.

In particular, disclosed is an apparatus for sealing or cutting tissuehaving a small engagement region such that the apparatus can be used inminimally invasive procedures. As will be discussed in detail, althoughthe apparatus comprises a small engagement region, the device isconfigured to provide sufficient clamping force and power to the targetsite to effectively cauterize tissue in a short amount of time.

Therapeutic Ultrasound Device

FIGS. 1A-1D illustrate a plurality of views of a sample therapeuticultrasound device 100 formed in accordance with the present disclosure.FIG. 1A illustrates an exploded view of the proximal end 104 of thetherapeutic ultrasound device 100 such that the interior components ofthe therapeutic ultrasound device 100 are visible. FIG. 1B illustrates across-sectional view of the therapeutic ultrasound device 100 showingthe arrangement of the internal components of the therapeutic ultrasounddevice 100 within the housing 110.

The disclosed therapeutic ultrasound device 100 is configured to usefocused ultrasound transducers or unfocused ultrasound transducersintegrated with a hemostatic clamping instrument. When deployed, theultrasound energy ablates the tissue contained between the heads,thereby forming a hemostatic plane of cauterization. This allowssurgeons to remove tumors, tissue, or organs without bleeding and alsoprovides a method to rapidly control bleeding in trauma situations,significantly reducing the risk of bleeding complications and reducingtrauma death due to exsanguination. This technology is applicable toopen and laparoscopic procedures. As will be discussed in more detailbelow, the disclosed therapeutic ultrasound device 100 can cauterizetissues over 3 cm thick and can assess whether treatment has beencompleted effectively.

As an overview, the therapeutic ultrasound device 100 may include adistal end 102 and a proximal end 104, wherein the distal end 102includes an engagement portion and the proximal end 104 includes a useractuation mechanism. For example, the proximal end 104 of thetherapeutic ultrasound device 100 includes a housing 110 that securesthe internal components of the therapeutic ultrasound device 100. Thehousing 110 can include a first half (e.g., left housing 110 a) and asecond half (e.g., right housing 110 b) that can be secured togetherusing a plurality of first fasteners 114 and second fasteners 116. Asshown in FIG. 1A, the plurality of first fasteners 114 and secondfasteners 116 are inserted through the plurality of openings 112 throughboth halves of the housing 110. In some examples, the first fasteners114 are screws and the second fasteners 116 are inserts that areconfigured to engage with each other and secure both halves of thehousing 110, however, those skilled in the art will recognize that othertypes of fasteners may be used without departing from the scope of thepresent disclosure. The first fasteners 114 and the second fasteners 116can comprise any structures that secure the housing 110 to thetherapeutic ultrasound device 100.

As shown in FIG. 1A, the housing 110 can be configured to secure thehandle 120 along with a plurality of other components that areconfigured to actuate the therapeutic ultrasound device 100.

The therapeutic ultrasound device 100 can include a latch guide 130. Asshown in FIG. 1A, the latch guide 130 can comprise a first portion 130 aand second portion 130 b that are configured to provide a path for thespring latch to travel. This can allow the lever to be “latched” in aclosed position. This can ensure that the tissue is compressed and heldduring treatment. In some examples, the two halves of the latch guide130 are configured to provide a symmetrical path, thereby distributingthe forces on the latch evenly when the latch is latched.

In some embodiments, the therapeutic ultrasound device 100 includes aconnector 140 and cable 150 that are configured to provide power to thetherapeutic ultrasound device 100. As will be discussed in more detail,the connector 140 and the cable 150 are configured to provide power tothe plurality of transducers located in the tissue engagement assembly400 through a plurality of wires and/or cables. The tissue engagementassembly 300 may also be referred to herein as a “jaw” assembly or“clamping” assembly

FIGS. 1A and 1B also illustrate a handle 120 located at the proximal end104 of the therapeutic ultrasound device 100. As shown in FIG. 1B, thehandle 120 may extend out from the housing 110 to allow the user to gripthe handle 120 with his/her fingers. In some embodiments, the handle120, along with the housing 110, provides a comfortable and ergonomicfit for the hand of the user. For example, the palm of the user can reston the exterior of the proximal end of the housing 110 and the thumb ofthe user can curl about the width of the base of the housing 110. Theremaining fingers of the user can be configured to fit in the opening ofthe handle 120 such that the user can pull back and release the handle120.

The handle 120 can be configured to actuate the movement of a jawassembly 400 located on the distal end 102 of the therapeutic ultrasounddevice 100. FIG. 1C illustrates the therapeutic ultrasound device 100with the proximal end 104 of the therapeutic ultrasound device 100 withthe housing 110 removed. As shown, the proximal end 104 of thetherapeutic ultrasound device 100 can include a spring 350 disposedabout the spring guide 352 adjacent to the handle 120. In some examples,the spring 350 and the spring guide 352 allow for the handle 120 toretract and return to its original position. In some embodiments, thespring 350 and the spring guide 352 are configured to allow the user tolatch the handle 120 such that the jaw assembly 400 remains clamped onthe tissue. Subsequent squeezing of the handle 120 can be unlatch thehandle to allow the spring to follow the spring guide 352 while thehandle 120 returns to a first position wherein the jaw assembly 400 isopened. In some embodiments, the handle 120 can be configured to includea memory chip (not illustrated). The memory chip can be configured tostore operating parameters for the therapeutic ultrasound device 100.

As will be discussed in more detail below, engagement of the handle 120can be configured to move the inner tube assembly 300 (shown in FIG. 1D)relative to the outer tube assembly 200. In some embodiments, the handle120 is adjacent to the rotation mechanism 220 which is configured toallow the jaw assembly 400 to be rotated about the longitudinal axis. Insome embodiments, the rotation mechanism 220 can allow rotation through±175 degrees about the longitudinal axis.

FIG. 1D illustrates an exploded view of the therapeutic ultrasounddevice 100 with the housing 110 removed. As will be discussed in turnbelow, the therapeutic ultrasound device 100 can include an outer tubeassembly 200, an inner tube assembly 300, and a jaw assembly 400.

As a brief overview, the outer tube assembly 200 can be disposed overthe inner tube assembly 300. The outer tube assembly 200 can include anouter tube 206 and an adaptor 210 located at a proximal end 204. In someembodiments, the adaptor 210 is configured to be attached to therotation mechanism 220. The adaptor 210 can be configured to enable thetherapeutic ultrasound device 100 to accommodate an outer tube 206and/or an inner tube 308 having varying diameters without needing toredesign the size and configuration of the attached handle assembly andother internal mechanisms of the therapeutic ultrasound device 100.

The inner tube assembly 300 can include an inner tube 308 and aconnector 330 located at a proximal end 304. As shown in FIG. 1D, theconnector 330 can be attached to the handle assembly. As will bediscussed in more detail below, the outer tube 206 and the adaptor 210are disposed over the inner tube 308 and the connector 330 respectively.The outer tube assembly 200 can be secured to the inner tube assembly300 using a plurality of fasteners. In some embodiments, the pluralityof fasteners comprise a retaining pin 230 and a retaining ring 232;however, as noted above the fasteners can comprise any shape orstructure without departing from the scope of the present disclosure.

As shown in FIG. 1D, the jaw assembly 400 can be located at the distalend 102 of the therapeutic ultrasound device 100. As will be discussedin more detail below, the jaw assembly 400 can include a top jaw 402 anda bottom jaw 404. The top jaw 402 and the bottom jaw 404 can be securedto the distal end 202 of the outer tube 206 and the distal end 302 ofthe inner tube 308 using a pivot pin 460 and an inner tube pin 470. Insome embodiments, the jaw assembly 400 can include a bushing 480 tosecure the pivot pin 460 in place and to maintain the space between ears420 of the top jaw 402 and the bottom jaw 404. In some examples, thebushing 480 can be configured to prevent rotation of the top jaw 402 andthe bottom jaw 404 within the jaw assembly 400.

The jaw assembly 400 can be secured to the outer tube 206 and the innertube 308 such that withdrawal or advancing of the inner tube 308relative to the outer tube 206 will cause the top jaw 402 and the bottomjaw 404 of the jaw assembly 400 to open and close. As noted above, andas will be discussed in more detail below, the engagement of the handle120 in a first direction will case movement of the inner tube 308,relative to the outer tube 206, in the first direction. This can causethe jaw assembly 400 to open. Similarly, release of the handle 120 in asecond direction can cause movement of the inner tube 308, relative tothe outer tube 206, in the second direction. This can cause the jawassembly 400 to close.

Outer Tube Assembly

FIGS. 2A-2G illustrate various embodiments of the outer tube assembly200. FIG. 2A illustrates an exploded view of certain components of theouter tube assembly 200; FIGS. 2B-2C illustrate the distal end 202 ofthe outer tube 206; FIG. 2D illustrates the proximal end 204 of theouter tube assembly 200; and FIGS. 2E-2H illustrate a plurality of viewsof the adaptor 210.

As discussed above, the outer tube assembly 200 can include the outertube 206, the adaptor 210, and the rotation mechanism 220. As shown inFIG. 2A, a proximal end of the outer tube 206 can be secured to theadaptor distal end 212 and the adaptor proximal end 214 can be attachedto the rotation mechanism 220. In some embodiments, the rotationmechanism 220 can comprise any material such as plastic, metal, rubber,etc.

As will be discussed in more detail below, the jaw assembly 400 can havea width ranging from 3 mm to 10 mm. In some embodiments, the jawassembly 400 can have a width ranging up to 15 mm. The jaw assembly 400should therefore be configured to apply sufficient clamping orengagement force to the target tissue in order to generate sufficientforce for treatment. In some embodiments, this can be 10-14 lbs. ofclamping force at the jaw assembly 400. In some embodiments, theclamping force at the jaw assembly 400 can be less than 10 lbs., between10-11 lbs., between 11 lbs.-12 lbs., between 12 lbs.-13 lbs., between 13lbs.-14 lbs., or greater than 14 lbs. In some embodiments, the clampingforce at the jaw assembly 400 can be any of 10 lbs., 11 lbs., 12 lbs.,13 lbs., or 14 lbs. To translate the force required for the device, theouter tube 206 can comprise a material that is configured to withstandthese forces. For example, the outer tube 206 can comprise double hardstainless steel tubing, aluminum, titanium, plastic, carbon fiber, etc.In some examples, the adaptor 210 can comprise a material that isconfigured to withstand these forces. For example, the adaptor 210 cancomprise double hard stainless steel tubing, aluminum, titanium,plastic, carbon fiber, etc. The outer tube 206 and the adaptor 210 willbe discussed in turn.

FIGS. 2B-2C illustrate the distal end 202 of the outer tube 206. Thedistal end 202 of the outer tube 206 can include a yoke 240 thatincludes a pair of arms. Each of the pair of arms of the yoke 240 caninclude an opening 242 and a slot 244. As shown in FIG. 1D, a pivot pin460 can be configured to fit through the opening 242 and the inner tubepin 470 can be configured to move along the slot 244. As will bediscussed in more detail below, movement of the inner tube pin 470 alongthe slot 244 can be configured to open and close the jaw assembly 400.

FIG. 2D illustrates the proximal end 204 of the outer tube assembly 200.The proximal end 204 of the outer tube assembly 200 can include theadaptor 210 having a distal end 212 and a proximal end 214. In someembodiments, the distal end 212 of the adaptor 210 is disposed over theproximal end of the outer tube 206. In some examples, the proximal end214 of the adaptor 210 is located within the rotation mechanism 220.FIGS. 2E-2H illustrates a plurality of views of the adaptor 210. Aproximal end 214 of the adaptor 210 can include a plurality of proximalgrooves 216. In some examples, the proximal grooves 216 are configuredto lock into a rotation knob. This can allow the user to rotate the tipof the therapeutic ultrasound device 100 (e.g., the jaw assembly 400).

Inner Tube Assembly

FIGS. 3A-3D illustrate various embodiments of the inner tube assembly300. FIG. 3A illustrates an exploded view of the components of the innertube assembly 300; FIG. 3B-3C illustrates a plurality of views of thedistal end 302 and proximal end 304 of the inner tube assembly 300; andFIG. 3D illustrates a cross-sectional view of the intersection of thecomponents of the inner tube assembly 300.

As shown in FIG. 3A, the inner tube assembly 300 can include the innertube 308, a spacer 310, and a connector 330. In some embodiments, theproximal end of the inner tube 308 is configured to engage with thespacer 310 and the distal end of the connector 330. In some examples,the inner tube 308, spacer 310 and connector 330 comprise a materialthat is configured to withstand these forces. For example, any of theinner tube 308, spacer 310, and connector 330 can comprise double hardstainless steel tubing, aluminum, titanium, plastic, carbon fiber, etc.In some embodiments, the inner tube and the outer tube can be flexibleor articulating. In some examples, the inner tube assembly 300 can behollow to allow cables and/or wires to run from the distal end 102 tothe proximal end 104 of the device.

As discussed with regard to the outer tube 206, the jaw assembly 400 canbe configured to apply sufficient clamping or engagement pressure to thetarget tissue in order to generate sufficient force for treatment. Totranslate the force required for the device, the inner tube 308 cancomprise a material that is configured to withstand these forces. Forexample, the inner tube 308 can comprise double hard stainless steeltubing, aluminum, titanium, plastic, carbon fiber, etc. In someembodiments, instead of a hollow tube, the inner tube 308 can insteadcomprise a solid pull rod (e.g., a rectangular pull rod). In exampleswhere the inner tube 308 is solid instead of hollow, traces (rather thancables or wires) can be used to provide power to the distal end 102 ofthe device.

As seen in FIG. 3A, the proximal end of the inner tube 308 can include aplurality of openings 306. Similarly, the spacer 310 can include aplurality of openings 312 and the distal end of the connector 330 caninclude a plurality of distal openings 336. In some examples, the spacer310 can be disposed over the proximal end of the inner tube 308 suchthat the plurality of openings 306 of the inner tube 308 aligns with theplurality of openings 312 of the spacer 310. In some embodiments, thespacer 310 is configured to provide an interference fit between theinner diameter of the connector 330 and the outer diameter of the innertube 308. In some embodiments, the distal end of the connector 330 canbe disposed over the spacer 310 and the proximal end of the proximal endof the inner tube 308. In some examples, the plurality of distalopenings 336 of the connector 330 are configured to align with theplurality of openings 312 of the spacer 310 and the plurality ofopenings 306 at the proximal end of the inner tube 308.

FIG. 3D illustrates a cross section of the inner tube assembly 300 andan embodiment of the connection between the inner tube 308, spacer 310,and a connector 330. As noted above, the plurality of openings 306, 312,336 can be aligned and secured by fasteners. In some embodiments, thefasteners securing the inner tube 308, spacer 310, and the connector 330are a plurality of dowel pins 320. In some examples, the inner tube 308,spacer 310, and the connector 330 can be bolted, welded, screwedtogether, or glued.

In some embodiments, the inner tube assembly 300 can include theconnector 330. As noted above, the connector 330 can be configured tosecure the inner tube 308 with the proximal end 104 of the therapeuticultrasound device 100 (e.g., the handle 120). In some examples, theproximal end of the inner tube assembly 300 and the outer tube assembly200 is configured to interface with a device (e.g., other than thehandle 120) that is configured to actuate the jaw assembly 400. Forexample, this can include a robotic articulating arm such that thetherapeutic ultrasound device 100 can be used in a variety ofapplications (e.g., endoluminal, laparascopic, thorascopic procedures).

As noted above, the connector 330 can include a plurality of distalopenings 336 at the distal end of the connector 330, a slot 334, and aproximal opening 332 at the proximal end of the connector 330. In someexamples, the slot 334 is configured to allow the inner tube 308 of theinner tube assembly 300 to translate through the therapeutic ultrasounddevice 100. The retaining pin 230 can be held in place by the proximalopening 332 and fit into the slot 334 of the connector 330. In someembodiments, the proximal end of the connector 330 is free floating.

As noted above, in some embodiments, the distal end 302 of the innertube assembly 300 can include a yoke 340 comprising a pair of arms. Insome examples, each of the pair of arms of the yoke 340 includes anopening 342. In some embodiments, the opening 342 is configured toreceive the inner tube pin 470.

As will be discussed in more detail below, the outer tube 206 candisposed over the inner tube 308 such that the yoke 240 of the outertube 206 is disposed about the yoke 340 of the inner tube 308. In someexamples, the openings 342 and the engaged inner tube pin 470 of thedistal end 302 of the inner tube 308 are aligned with the slot 244 ofthe distal end 202 of the outer tube 206. This can allow the distal end302 of the inner tube 308 to move the inner tube pin 470 within the slot244 of the distal end 202 of the outer tube 206.

Jaws and Jaw Assembly

FIGS. 4A-4F illustrate an embodiment of individual jaws of the jawassembly 400. Although only half of the jaw assembly 400 is illustratedin FIGS. 4A-4F, the jaw illustrated in FIGS. 4A-4F can describe the topjaw 402 and/or the bottom jaw 404.

In some embodiments, the jaws 402, 404 include an ear 420 on theproximal end 408 of the jaw 402, 404 and a body 430 on the distal end406 of the jaw 402, 404. The jaw 402, 404 can include an opening 422adjacent to the ears 420 and between the ear 420 and the body 430. Aswill be discussed in more detail below, the opening 422 can beconfigured to receive the pivot pin 460 such that the jaw 402, 404 canrotate about the pivot pin 460. In some embodiments, the jaw 402, 404can be comprised of stainless steel or ceramics. In some examples, thejaws 402, 404 can have a width between 3 mm and 10 mm. In someembodiments, the jaws 402, 404 can have a width between 1 mm and 15 mm.In some embodiments, the jaws 402, 404 can have any of the widths of 1mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm,13 mm, 14 mm, and 15 mm. In some embodiments, the jaws 402, 404 can havea length between 5 mm and 100 mm. In some embodiments, the jaws 402, 404can have a length between any of the ranges of 5 mm-10 mm, 10 mm-15 mm,15 mm-20 mm, 20 mm-25 mm, 25 mm-30 mm, 30 mm-35 mm, 35 mm-40 mm, 40mm-45 mm, 45 mm-50 mm, 50 mm-55 mm, 55 mm-60 mm, 60 mm-65 mm, 65 mm-70mm, 70 mm-75 mm, 75 mm-80 mm, 80 mm-85 mm, 85 mm-90 mm, 90 mm-95 mm, or95 mm-100 mm. In some embodiments, the jaws 402, 404 can have any of thelengths of 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm,50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm,and 100 mm.

In some embodiments, the ear 420 includes a slot 424. The slot 424 canbe curved (as shown in FIG. 4A), straight, or any other configuration.The slot 424 can be configured to receive the inner tube pin 470. Aswill be discussed in more detail below, movement of the inner tube pin470 within the slot 424 can be configured to cause the pair of jaws 402,404 of the jaw assembly 400 to move (e.g., open and close).

In some embodiments, the body 430 comprises an opening 434 configured toreceive an acoustic stack (not shown). As shown in FIGS. 4A and 4E, theopening 434 can be rectangular in shape; however, the opening 434 can beany shape so long as it can receive and secure an acoustic stack. Insome embodiments, the body 430 forms a shell 432. As will be discussedin more detail below, the shell 432 of the body 430 can be configured toprovide an air-pocket for a transducer formed with the acoustic stack.

The base of the body 430 can further include an opening 490. The opening490 can be configured to allow a cable (not illustrated) of the acousticstack to be threaded through the opening 490. The cable can then be runthrough the outer tube assembly 200/inner tube assembly 300 where it isattached to the cable 150 (as shown in FIG. 1A). In this way, a powersource can be provided to the acoustic stack to power the therapeuticultrasound device 100.

In some embodiments, the distal end 406 of the jaw 402, 404 includesteeth 410. For example, as shown in FIGS. 4A-4E, the teeth 410 can beformed as wave-like folds in the distal end 406 of the jaw 402, 404adjacent to the body 430. In other embodiments, the teeth 410 are formedalong the edge of the distal end 406 of the jaw 402, 404 or along theentire perimeter of the body 430. The teeth 410 can have any shape orconfiguration, such as serrated, triangular, needle-like, etc. As well,the teeth 410 can be located on one or both of the jaws 402, 404. Insome embodiments, as the jaw assembly 400 closes on the target tissue,the tissue can be inclined to move out of place. The teeth 410 aretherefore configured to engage with and retain the target tissue as thejaw assembly 400 clamps downward.

FIGS. 5A-5D detail an example of the connection between the jawassemblies 400 on the distal end 102 of the therapeutic ultrasounddevice 100. As discussed above, the jaw assembly 400 can be assembled toengage with the distal end 202 of the outer tube 206 and the distal end302 of the inner tube 308. The jaw assembly 400 illustrated in FIGS.5A-5D includes an acoustic stack 500 with a cable 440. In some examples,the proximal end of the jaw assembly 400 is configured to interface witha device (e.g., other than the distal end 202 of the outer tube 206 andthe distal end 302 of the inner tube 308) that is configured to actuatethe jaw assembly 400. For example, this can include a roboticarticulating arm such that the therapeutic ultrasound device 100 can beused in a variety of applications (e.g., endoluminal, laparascopic,thorascopic procedures).

As discussed above, the outer tube 206 can be disposed over the innertube 308 such that the pair of arms of the yoke 340 of the inner tube308 are generally aligned with the pair of arms of the yoke 240 of theouter tube 206. This can be better seen in the cross-sectional view ofFIGS. 5C and 5D where the outer tube 206 is disposed over the inner tube308. To allow the inner tube 308 to fit within and move relative to theouter tube 206, the diameter of the inner tube 308 can be less than theouter tube 206. For example, the inner tube 308 can have a diameter of0.103 inches and the outer tube 206 can have a diameter of 0.133 inches.

As seen in FIGS. 5A-5D the yoke 240 of the outer tube 206 and the yoke340 of the inner tube 308 are spaced apart to allow the ears 420 of thejaw assembly 400 to fit between. In some embodiments, the pair of armsof the yoke 240 and the yoke 340 are sufficiently long such that thereis clearance to allow the ears 420 of the top jaw 402 and the bottom jaw404 to rotate freely about the pivot pin 460.

As discussed above, each of the pair of arms of the yoke 240 of theouter tube 206 can include an opening 242 and a slot 244. Theseopenings, along with the opening 342 located in each of the pair of armsof the yoke 340 of the inner tube 308, are configured to retain and movethe top jaw 402 and the bottom jaw 404 of the jaw assembly 400. As notedabove, in some embodiments this can be accomplished using a combinationof the pivot pin 460 and the inner tube pin 470.

As shown in FIGS. 5A-5D, the opening 422 of each of the top jaw 402 andthe bottom jaw 404 are aligned with the openings 242 on each of the pairof arms of the yoke 240 of the outer tube 206. In some embodiments, apivot pin 460 is fitted through and secured to the outer tube 206 suchthat the top jaw 402 and the bottom jaw 404 of the jaw assembly 400 areretained between the yoke 240 of the outer tube 206. The pivot pin 460may also be configured to allow the top jaw 402 and the bottom jaw 404to rotate about the pivot pin 460.

As discussed above, the inner tube pin 470 can be configured to causethe top jaw 402 and the bottom jaw 404 of the jaw assembly 400 to openand close. As shown in FIGS. 5A through 5D, the opening 342 in the pairof arms of the yoke 340 is aligned with the slot 244 in the pair of armsof the yoke 240. As illustrated in FIGS. 5B-5D, the ears 420 of the topjaw 402 and the bottom jaw 404 of the jaw assembly 400 are locatedbetween the yoke 340, such that a portion of the slot 424 intersects theplane on which the slot 244 of the outer tube 206 extends.

As better seen in the cross-sectional views in FIGS. 5B-5D, the innertube pin 470 can be fitted through and secured to each of the openings342. In some embodiments, the inner tube pin 470 is press-fit into thebushing 480. In some embodiments, ends of the inner tube pin 470 areconfigured to extend through the slot 244 of the outer tube 206 suchthat the inner tube pin 470 can move freely along the slots 424. Theinner tube pin 470 can also be fitted through each of the slots 424 ofthe ears 420 in the top jaw 402 and bottom jaw 404. This configurationcan allow the inner tube 308 to advance or retract the inner tube pin470 along the slot 244 as the inner tube 308 can be advanced orretracted relative to the outer tube 206. As the inner tube pin 470moves along the length of the slot 244, the inner tube pin 470 isconfigured to move along the track of the slot 424 in each of the ears420. As the inner tube pin 470 moves in a first direction, the innertube pin 470 moves to a first end of the slot 424, causing the jawassembly 400 to open. Similarly, as the inner tube pin 470 moves in asecond direction, the inner tube pin 470 moves to a second end of theslot 424, causing the jaw assembly 400 to close.

In some embodiments, a wire guide 450 is configured to fit within theouter tube 206 distal to the inner tube 308. The wire guide 450 may beconfigured to protect the wires located between the ears 420 of the jaws402, 404 such that the wires are not impinged in the jaws 402, 404. Thewire guide 450 may include an opening to receive the cable 440 and guideit along the length of the interior of the inner tube 308. In someembodiments the wire guide 450 can be comprised of a compliant material.For example, the material can be a thermoplastic such as a resinpolymer.

In some embodiments, the jaw assembly 400 includes a bushing 480. Asnoted above, the bushing 480 can be located between the ears 420 of thetop jaw 402 and the bottom jaw 404. The bushing 480 can be configured tosecure the pivot pin 460 in place and to maintain the space between theears 420 of the top jaw 402 and the bottom jaw 404. The bushing 480 can,for example, keep the ears 420 of the top jaw 402 and the bottom jaw 404separated such that the wires do not get impinged. As well, the bushing480 can be configured to retain the draw pin 470. As discussed above, insome examples, the draw pin 470 is pressed into the bushing 480. Thebushing 480 may also or alternatively be configured to prevent rotationof the top jaw 402 and the bottom jaw 404 within the jaw assembly 400.In some embodiments, the bushing 480 can be comprised of a material suchas stainless steel.

FIG. 5E illustrates a cross-sectional view of the distal end 102 of thetherapeutic ultrasound device 100 through the pivot pin 460. Asillustrated, the plurality of ears 420 of the top jaw 402 and the bottomjaw 404 are located between the pair of arms of the yoke 240 of theouter tube 206. In some embodiments, as discussed above, the pivot pin460 extends through the openings 422 in the top jaw 402 and the bottomjaw 404 to allow the pair of jaws to rotate. As noted above, the wireguide 450 can be located near the base of the yoke 240 and adjacent tothe ears 420.

FIG. 5F illustrates a cross-sectional view of the distal end 102 of thetherapeutic ultrasound device 100 through the inner tube pin 470. Asnoted above, the inner tube pin 470 can extend through the slot 244 ofthe outer tube 206 and through the distal end 302 of the yoke 340. Insome embodiments, the inner tube pin 470 also extends through the slot424 in each of the top jaw 402 and the bottom jaw 404. A bushing 480 canbe located between the ears 420 of the pair of jaws of the jaw assembly400. As discussed, this can help to maintain the space between the ears420 of the pair of jaws of the jaw assembly 400 and prevent rotation ofthe pair of jaws of the jaw assembly 400.

The jaw assembly 400 can be configured such that both the top jaw 402and the bottom jaw 404 are movable. In some embodiments, only one of thepair of jaws of the jaw assembly 400 is movable. In some embodiments,the top jaw 402 and bottom jaw 404 form an angle when open and themovement of the top jaw 402 and the bottom jaw 404 is a scissor-likemovement. In other embodiments, the top jaw 402 and the bottom jaw 404are parallel to one another and open and close such that the pair ofjaws remain in parallel with one another.

Acoustic Stack

In some embodiments, the therapeutic ultrasound device 100 can includean acoustic stack 500 within each jaw of the jaw assembly 400. In someembodiments, the jaw assembly 400 can include a jaw with an acousticstack 500 and a jaw without an acoustic stack. FIGS. 6A-6C, 7A-7C, and8A-8C illustrate a plurality of embodiments of the acoustic stack 500.

FIGS. 6A-6C illustrate a first embodiment of an acoustic stack 500 a.The acoustic stack 500 a can include an acoustic wave generating layer510 a layer, an adhesive 520 a layer, and a matching layer 540 a. Insome embodiments, the 510 a layer is a piezoelectric transducer (PZT).In some embodiments, the 510 a layer can be a capacitive machinedultrasound transducer (CMUT) or any other silicon chip comprisingmachined drums that are configured to apply a voltage and pulse. In someexamples, the 510 a layer can have a width of 2.6 mm and a length of 15mm.

In some examples, the matching layer 540 a is configured to allow thetransmission of acoustic energy into a target site by matching theacoustic wave propagation from the 510 a layer (e.g., the PZT layer) tothe target tissue. As the frequency of the acoustic wave is a functionof the thickness and type of material passing through it, the matchinglayer 540 a is configured to prevent the wave from getting reflectedfrom the target tissue. In order for a wave to propagate from onematerial to the next they should have similar acoustic impedances. Ifthere is an impedance mismatch the wave is reflected. The degree ofreflection depends on the degree of mismatch.

One or more electrodes 530 a can be located on an end of the acousticstack 500 a between each layer of the PZT 510 a, adhesive 520 a, andmatching layer 540 a. In some embodiments, the electrodes 530 a cancomprise copper. In other embodiments the electrodes 530 a can compriseany conductive material. A cable 440 can be located on an end of theacoustic stack 500 a and electrically in contact with the electrodes 530a to provide power to the acoustic stack 500 a. In some embodiments, asshown in FIG. 6C, the PZT 510 a can include a plurality of slots 512 a.The slots 512 a can be configured to can be configured to produce a moreuniform acoustic field along the length of the transducer 600 a.

FIGS. 7A-7C illustrate a second embodiment of an acoustic stack 500 b.As with the acoustic stack 500 a, the acoustic stack 500 b can include aPZT 510 b layer, an adhesive 520 b layer, and a matching layer 540 b.One or more electrodes 530 b can be located on an end of the acousticstack 500 b between each layer of the PZT 510 b, adhesive 520 b, andmatching layer 540 b. As with the acoustic stack 500 a, a cable 440 canbe electrically connected to the plurality of electrodes 530 b toprovide power to the acoustic stack 500 b.

FIGS. 8A-8C illustrate a third embodiment of an acoustic stack 500 c. Asdiscussed with regard to the acoustic stack 500 a, 500 b, the acousticstack 500 c can include a PZT 510 c layer, an adhesive 520 c layer, anda matching layer 540 c. As illustrated in FIG. 8C, the PZT 510 c layercan comprise a plurality of side-by-side PZTs. In the example shown, thePZT 510 c layer includes three (3) adjacent PZTs. One or more electrodes530 c can be located in layers above and below the PZT 510 c layer. Asshown in FIG. 8C, the electrodes 530 c can be aligned above and belowthe PZT 510 c layer such that each of the plurality of PZTs 510 c areconnected by an electrode 530 c. In some embodiments, as seen in FIG.8C, the adhesive 520 c can be configured to receive a plurality ofelectrodes 530 c. A cable 440 can be electrically connected to at leastone of the plurality of electrodes 530 c to provide power to theacoustic stack 500 c.

The matching layer 540 in each of the above-described embodiments of theacoustic stack 500 can be configured to adapt the sound speed of the PZT510 with the sound speed through the tissue to which the therapeuticultrasound device is being applied, which tissue may have a higherimpedance. The matching layer 540 can comprise graphite or fluoropolymerand the surface of the matching layer 540 can be coated with parylene orany other material that provides the matching layer 540 with a nonstickand/or biocompatible surface.

In some embodiments, the matching layer 540 can be attached to thesurface of the PZT 510 with the adhesive 520 layer. The adhesive 520layer can be an epoxy or a layer of metal formed from soldering the PZT510 to the matching layer 540.

As will be discussed in more detail below, each of the acoustic stacks500 a, 500 b, and 500 c are configured to be secured in at least one ofthe jaws 402, 404 of the jaw assembly 400. The acoustic stack, whensecured in the jaw 402, 404 forms a transducer that can producetherapeutic ultrasound. As each of the acoustic stacks 500 a, 500 b, 500c are simplistic in construction, the transducer formed is capable ofproducing a higher intensity of energy in comparison to other transducerconstructions currently in existence. In this way, the small size of thejaw assembly (e.g., 3 mm-15 mm) can efficiently seal and/or cut tissue.

Each of the acoustic stacks 500 a, 500 b, and 500 c are configured toprovide the acoustic field and power described above. In someembodiments, each of the acoustic stacks 500 a, 500 b, 500 c provide forvarying resultant acoustic field maps when driven in water. Each of theacoustic stacks 500 a, 500 b, and 500 c differ in the complexity inconstruction. In some examples, the acoustic stack 500 b has the mostsimplistic construction compared to the construction of the acousticstack 500 c.

Transducer and Relationship Between Applied Power and Force

In some examples, as discussed above, by placing the ultrasoundtransducers on opposing arms of a clamp, we achieve a well-confined andcontrolled high intensity region midline between the transducers wherethe absorbed energy cauterizes the tissue progressing from the midlinetoward the transducers resulting in a complete plane of cauterization.Particularly where DTU is used, significant collateral damage due tohigh focal gains and long transmission paths through intervening tissuecan be avoided and instead provide for invasive or minimally-invasiveprocedures. The use of DTU can provide the ability to induce planes ofcauterization/ablations to treat volumes (up to ˜30 cm³) of tissue inseconds as opposed to the raster scanning technique frequently requiredwith transcutaneous HIFU. Existing raster scanning can require longtreatment times (e.g., hours) to ablate a comparable volume as ablatedusing the presently disclosed device.

In some embodiments, ablation occurs in seconds due to the heatgeneration via ultrasound absorption and because the high intensityregion is well-contained within the midline of the transducer heads. Inthe disclosed device, there is no collateral thermal spreading beyondthe region of interest, and the face of the transducers does not heatexcessively, thus preventing tissue adhering to the applicator. Ablatedtissue is resorbed by the body similar. The disclosed device has aconsiderable advantage over existing ablative technologies in thatablation and hemostasis can be reached in significantly quickertreatment time and any complications due to thermal spreading and tissueadherence to the device are fully avoided. In conjunction with theinnovative therapy modality/device, ultrasound also affords the abilityto interrogate the treated region to evaluate the progression of thetherapy with the same transducers that are administering the therapy.

In some embodiments, to provide treatment at a target site, sufficientclamping force and power from the jaw assembly 400 must be delivered.Particularly when the jaw assembly 400 is within the 3 mm-15 mm range,the configuration of the transducers of the jaw assembly 400 can berelevant to providing sufficient power to the target site.

In most constructions of transducers, the transducer includes a backinglayer, a copper electrode layer, a PZT layer, a second copper electrodelayer, and another backing layer. Each of these layers, in particularthe plurality of backing layers, provide an increased resistance thatlimits the power that can be delivered by the transducer. However,conventional transducers are built with these components to form atransducer that can be operated over a broad range of frequencies.

In contrast, the disclosed therapeutic ultrasound device 100 includes atransducer in the jaw assembly 400 that is constructed to operate withina narrow range of frequencies so as to provide for greater power/cm³. Insome embodiments, the transducer can be designed to work at anyultrasound frequency. For example, the transducer can be designed towork between 1 MHz and 10 MHz. In some embodiments, the disclosedtransducer of the therapeutic ultrasound device 100 is driven by a radiofrequency (RF) signal generator that produces between 10 W to 200 W ofelectricity. The transducer of the therapeutic ultrasound device 100 isconfigured to convert the electrical power into acoustic power. Thedisclosed transducer of the therapeutic ultrasound device 100 isconfigured to function at between 60%-80% efficiency. For example, theacoustic power generated by the transducer is approximately 200 Watts.FIGS. 9A and 9B illustrate cross-sectional embodiments of each of thepair of jaws 402, 404 that form transducer 600 a and transducer 600 a.Each and/or both of these embodiments can be formed within the jawassembly 400.

FIG. 9A illustrates an embodiment of the transducer 600 a in one or bothof the jaws 402, 404. As shown, the transducer 600 a can include anacoustic stack 500 located in the shell 432 of the jaws 402, 404. Asdiscussed above, the acoustic stack 500 can comprise a matching layer540 and a PZT 510. In contrast to conventional transducers that includea backing layer, the disclosed transducer 600 a has an air-filled pocket610 backing that is configured to ensure high efficiency as ultrasounddoes not travel well through air. The acoustic wave generating layer(e.g., PZT 510 layer), is configured to generate acoustic waves throughboth sides of the 510 layer. As air is the greatest impedance mismatchpossible for an acoustic wave generator (e.g., PZT), the air-filledpocket 610 causes most of the acoustic wave to be reflected back on theair-filled side and into the tissue.

As noted above, the present construction of the transducer does notinclude the many layers present (e.g., the plurality of electrode layersand backing layers) in conventional construction of transducers. Theembodiments of the transducer 600 a therefore encounters less impedanceand can generate significantly more power over a relatively shortdistance when compared to conventional transducers. As well, the fewerlayers included in a transducer reduces the amount of loading the PZTlayer experiences. This can therefore enable the PZT layer to generatemore acoustic power at a given electrical power. This increased power,along with the force that can be produced in the jaw assembly of thetherapeutic ultrasound device 100 disclosed above, can allow therelatively small size of the jaw assembly 400 (e.g., 3 mm-15 mm) to sealand/or cut tissue at a target location over a short amount of time. Theability of the therapeutic ultrasound device 100 to seal and/or dividetissue is a function of energy delivered to the tissue, the pressurewith which the tissue is clamped, and the amount of time treatment isapplied (e.g., Power=Energy/Time). An example of this relationship isillustrated in FIG. 14.

FIG. 9B illustrates another embodiment of the transducer 600 b that canbe formed in one or both of the jaws 402, 404. Similar to the transducer600 a, the transducer 600 b can include an acoustic stack 500 located inthe shell 432 of the jaws 402, 404. As well, the acoustic stack 500 cancomprise a matching layer 540 and a PZT 510. In addition to theair-filled pocket 610, the transducer 600 b includes a lining 620 thatserves to further electrically isolate the inside surface of the shell432. As discussed with regard to the air-filled pocket 610, the lining620 is configured to further improve the efficiency of the ultrasound.In some examples, the lining 620 comprises a heat resistant polymer. Insome embodiments, the lining 620, by further electrically isolating theinside surface of shell 432, further prevents the power generated fromthe transducer from being dissipated. As noted above, this can increasethe power generated in the transducer 600 b. Along with the force thatcan be produced in the jaw assembly 400 of the therapeutic ultrasounddevice 100 disclosed above, the configuration of the transducer 600 bcan allow the relatively small size of the jaw assembly 400 (e.g., 3mm-15 mm) to seal and/or cut tissue at a target location over a shortamount of time. As discussed above, the ability of the therapeuticultrasound device 100 to seal and/or divide tissue is a function ofenergy delivered to the tissue, the pressure the tissue is clamped with,and the amount of time treatment is applied (e.g., Power=Energy/Time).

In some embodiments, when the jaw assembly 400 of the therapeuticultrasound device 100 engages a target site, the transducer 600 a, 600 bcan launch an acoustic wave toward the target site in a medium (e.g.,tissue) and receive echoes as the acoustic wave reflects off the tissue.For example, a wavelength of 0.15 mm can be produced using 10 MHz, awavelength of 0.3 mm can be produced using 5 MHz, a wavelength of 0.4 mmcan be produced using 3.5 MHz, and a wavelength of 1.5 mm can beproduced using 1 MHz. In some examples, the target site may be diseasedor not diseased tissue, muscle, vasculature, etc. In some examples, thetransmitted ultrasound waves can become nonlinear as they propagatethrough the tissue, and the nonlinear propagation can generate harmonicsin the acoustic beam that develop at or near the focal region of thetransducer 600 a, 600 b from which they are transmitted. In someembodiments, at the focal region, the harmonic content can causeacoustic beam narrowing, enhanced tissue heating and proximal focalshifts. In some examples, the focal region can refer to a point, area,or volume at which the intensity of the transducer 600 a, 600 b sourceis the highest.

As illustrated in FIGS. 14A-14D, the tissue can be heated to between 40°C. and 100°. As illustrated in FIG. 11, the velocity of sound in tissueis temperature dependent. As the tissue temperature increases toapproximately 50° C., protein denaturation occurs and results in aninflexion point in the slope of the sound velocity vs. temperature plot.Near 50° C., the slope can be zero.

FIG. 12A illustrates that the relationship between maximum temperatureand acoustic energy followed a power law relationship versus intensitywith time fixed, FIG. 12B illustrates a linear relationship versus timewith power and intensity fixed, and FIG. 12C illustrates a linearrelationship versus intensity at a fixed time. These preliminary trendscan be configured to predict the energy, time, and intensity required toachieve desired temperatures. FIG. 12D further indicates the timerequired to reach a given temperature at a specific power.

In some examples, the jaw assembly 400 is configured to monitor thepower that is reflected back as the ultrasound is passed through thetarget site. In some embodiments, the power reflected back can help thetherapeutic ultrasound device 100 to determine the degree in whichtarget site has been cauterized (e.g., sealed or cut). In some examples,this can be determined, over time, as tissue is being cauterized and theacoustic impedance changes. This change in impedance can affect theamount of power reflected back and sensed by the jaw assembly 400.

In some embodiments, the therapeutic ultrasound device 100 can sense(e.g., significant) change in the voltage standing wave ratio (VSWR)between the two transducers in the jaw assembly 400 as an indicator forending of therapy, which is defined as complete ablation and hemostaticcontrol. In vivo experiments were conducted in which the jaw assembly400 was positioned on porcine kidneys which were instrumented withthermocouples. Therapy was administered until a significant change inVSWR was observed (average time of approximately 140 seconds). Uponresection of the distal portion of the kidney, no bleeding was observed(immediately after and for a 10-minute time frame) and the ablationplane was clearly and completely demarked. Furthermore, treatment timesexceeding the VSWR inflexion point did not show excessive heatingadjacent to the clamp heads. The results of these studies confirmed thatVSWR is a potentially viable mechanism for determining end-of-treatmenttime thus ensuring robust ablation and hemostasis while at the same timeavoiding overtreatment and possible collateral damage due to thermalspread.

FIGS. 13A-13D illustrate the use of VSWR to determine end of treatment.Turning first to FIG. 13A, an inflection point is observed in treatmentsin which 43° C. was exceeded. FIG. 13B illustrates that extendedtreatments (e.g., 240 s) indicated a slight elevation in temperaturesadjacent to the clamp as opposed to significant temperature increases inthe focal region. FIG. 13C illustrates an example of where using theVSWR to determine the end of therapy in vivo results in completehemostasis. Lastly, FIG. 13D illustrates that internal temperaturereached approximately 50° C. at 140 s during in vivo experiments.

In some examples, in addition to the ultrasound generated by thetransducer 600 a, 600 b, the force applied by the jaw assembly 400 canbe effective in sealing and/or cutting the target tissue. In someembodiments, particularly with vessel sealing, there exists arelationship between the clamping force applied by the jaw assembly 400and the power required. An example of the relationship is illustrated inFIG. 14. For example, when the clamping force applied by the jawassembly 400 is too low, a higher energy from the transducer 600 a, 600b is required and vice versa.

In some embodiments, as discussed above, the jaw assembly 400 can beconfigured to provide 10 lbs. of clamping force. In some embodiments,this can range between 10-14 lbs. of clamping force at the jaw assembly400. In some embodiments, the clamping force at the jaw assembly 400 canbe less than 10 lbs., between 10-11 lbs., between 11 lbs.-12 lbs.,between 12 lbs.-13 lbs., between 13 lbs.-14 lbs., or greater than 14lbs. In some embodiments, the clamping force at the jaw assembly 400 canbe any of 10 lbs., 11 lbs., 12 lbs., 13 lbs., or 14 lbs. In order togenerate the aforementioned clamping force in the jaw assembly400—particularly when the top jaw 402 and the bottom jaw 404 have awidth of only 3 mm-10 mm—sufficient force must be applied at the handle120 of the therapeutic ultrasound device 100. In some embodiments, theratio of the transfer of force is about 20:1. In some examples, theratio of the transfer of force is between 15:1 to about 20:1; the ratiois 15:1, 16:1, 17:1, 18:1, 19:1, or 20:1; or the ratio is between 15:1and 16:1, the ratio is between 16:1 and 17:1, the ratio is between 17:1and 18:1, the ratio is between 18:1 and 19:1, or the ratio is between19:1 and 20:1. In some embodiments, the ratio of the transfer of forcesatisfies the FDA requirement wherein 95% of the female population canactuate the therapeutic ultrasound device 100. In some examples, thecombination of the pivot pin 460 and the angle and/or curvature of theslot 424 on the ears 420 of the pair of jaws 402, 404 are configured toincrease the moment on the jaw assembly 400 to help increase the forcegenerated at the jaw assembly 400.

FIG. 10 illustrates the relationship between the clamping forcegenerated by the jaw assembly 400 versus the jaw opening angle for astraight slot 424 compared to a curved slot 424 in the ears 420 of thepair of jaws 402, 404. As shown in FIG. 10, a straight slot 424 canprovide a jaw clamp force that ranges between approximately 5.0 lbs. and6.8 lbs. over a range of approximately 25 to 0 degrees. In anotherexample, a straight slot 424 can provide a jaw clamp force that rangesbetween approximately 7.50 lbs. and 8.50 lbs. over a range ofapproximately 15 to 0 degrees. By comparison, a curved slot 424 canprovide a jaw clamp force that ranges between 2 lbs. and 10 lbs. over arange of 15 to 0 degrees. As illustrated, a curved slot 424 can beconfigured to generate a moment to provide a greater jaw clamping forceover a smaller range of angles.

In addition to the force applied by the jaw assembly 400 and the powergenerated by the transducer 600, the time in which the jaw assembly 400is applied to the target tissue can affect whether the tissue and/orvessel is sealed or cut. In some embodiments the Energy to seal is afunction of clamping pressure, acoustic power, and time:

E(s)=F(cp(t),ap(t))

In some embodiments, tissue and/or vessels can be sealed withinapproximately 2 seconds. In some examples, tissue and/or vessels can becut within approximately 10 seconds. This time is in contrast to thermalor RF technology which requires approximately 10 to 25 seconds forcomparable tissue. As well, use of ultrasound in the transducer 600 canprovide for controlled tissue sealing and/or cutting within a very shorttime frame. In some examples, the transducer 600 can seal and/or cuttissue within 2 to 10 seconds, depending on the tissue. For example, a 5mm vessel can be sealed using 100 Joules of acoustic energy. Similarly,the 5 mm vessel can be cut with an additional 50 Joules of acousticenergy. In some embodiments, a 5 mm vessel requires about 270 Joules toseal. In some examples, a 5 mm vessel requires about 640 Joules todivide. The amount of energy required will vary depending on tissue typeand vessel size as well as the acoustic regime used to treat the targettissue.

Certain Terminology

Terms of orientation used herein, such as “top,” “bottom,” “horizontal,”“vertical,” “longitudinal,” “lateral,” and “end” are used in the contextof the illustrated embodiment. However, the present disclosure shouldnot be limited to the illustrated orientation. Indeed, otherorientations are possible and are within the scope of this disclosure.Terms relating to circular shapes as used herein, such as diameter orradius, should be understood not to require perfect circular structures,but rather should be applied to any suitable structure with across-sectional region that can be measured from side-to-side. Termsrelating to shapes generally, such as “circular” or “cylindrical” or“semi-circular” or “semi-cylindrical” or any related or similar terms,are not required to conform strictly to the mathematical definitions ofcircles or cylinders or other structures, but can encompass structuresthat are reasonably close approximations.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include or do not include certain features, elements, and/orsteps. Thus, such conditional language is not generally intended toimply that features, elements, and/or steps are in any way required forone or more embodiments.

Disjunctive language such as the phrase “at least one of X, Y, or Z,”unless specifically stated otherwise, is otherwise understood with thecontext as used in general to present that an item, term, etc., may beeither X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z).Thus, such disjunctive language is not generally intended to, and shouldnot, imply that certain embodiments require at least one of X, at leastone of Y, or at least one of Z to each be present.

The terms “approximately,” “about,” and “substantially” as used hereinrepresent an amount close to the stated amount that still performs adesired function or achieves a desired result. For example, in someembodiments, as the context may dictate, the terms “approximately,”“about,” and “substantially” may refer to an amount that is within lessthan or equal to 10% of the stated amount. The term “generally” as usedherein represents a value, amount, or characteristic that predominantlyincludes or tends toward a particular value, amount, or characteristic.As an example, in certain embodiments, as the context may dictate, theterm “generally parallel” can refer to something that departs fromexactly parallel by less than or equal to 20 degrees.

Unless otherwise explicitly stated, articles such as “a” or “an” shouldgenerally be interpreted to include one or more described items.Accordingly, phrases such as “a device configured to” are intended toinclude one or more recited devices. Such one or more recited devicescan also be collectively configured to carry out the stated recitations.For example, “a processor configured to carry out recitations A, B, andC” can include a first processor configured to carry out recitation Aworking in conjunction with a second processor configured to carry outrecitations B and C.

The terms “comprising,” “including,” “having,” and the like aresynonymous and are used inclusively, in an open-ended fashion, and donot exclude additional elements, features, acts, operations, and soforth. Likewise, the terms “some,” “certain,” and the like aresynonymous and are used in an open-ended fashion. Also, the term “or” isused in its inclusive sense (and not in its exclusive sense) so thatwhen used, for example, to connect a list of elements, the term “or”means one, some, or all of the elements in the list.

Overall, the language of the claims is to be interpreted broadly basedon the language employed in the claims. The language of the claims isnot to be limited to the non-exclusive embodiments and examples that areillustrated and described in this disclosure, or that are discussedduring the prosecution of the application.

Summary

Although various covers have been disclosed in the context of certainembodiments and examples (e.g., surgical assemblies and methods), thisdisclosure extends beyond the specifically disclosed embodiments toother alternative embodiments and/or uses of the embodiments and certainmodifications and equivalents thereof. For example, any of the disclosedcovers can be used on the leading edge of other types of devices, suchas wings, vanes, blades, propellers, impellers, or otherwise. Variousfeatures and aspects of the disclosed embodiments can be combined withor substituted for one another in order to form varying modes of theconveyor. The scope of this disclosure should not be limited by theparticular disclosed embodiments described herein.

Certain features that are described in this disclosure in the context ofseparate implementations can also be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation can also be implemented inmultiple implementations separately or in any suitable sub-combination.Although features may be described above as acting in certaincombinations, one or more features from a claimed combination can, insome cases, be excised from the combination, and the combination may beclaimed as any sub-combination or variation of any sub-combination.

Moreover, while operations may be depicted in the drawings or describedin the specification in a particular order, such operations need not beperformed in the particular order shown or in sequential order, and alloperations need not be performed, to achieve the desirable results.Other operations that are not depicted or described can be incorporatedin the example methods and processes. For example, one or moreadditional operations can be performed before, after, simultaneously, orbetween any of the described operations. Further, the operations may berearranged or reordered in other implementations. Also, the separationof various system components in the implementations described aboveshould not be understood as requiring such separation in allimplementations, and it should be understood that the describedcomponents and systems can generally be integrated together in a singleproduct or packaged into multiple products. Additionally, otherimplementations are within the scope of this disclosure.

Some embodiments have been described in connection with the accompanyingfigures. The figures are drawn and/or shown to scale, but such scaleshould not be limiting, since dimensions and proportions other than whatare shown are contemplated and are within the scope of the presentdisclosure. Distances, angles, etc. are merely illustrative and do notnecessarily bear an exact relationship to actual dimensions and layoutof the devices illustrated. Components can be added, removed, and/orrearranged. Further, the disclosure herein of any particular feature,aspect, method, property, characteristic, quality, attribute, element,or the like in connection with various embodiments can be used in allother embodiments set forth herein. Additionally, any methods describedherein may be practiced using any device suitable for performing therecited steps.

In summary, various embodiments and examples of leading edge assemblieshave been disclosed. Although the assemblies have been disclosed in thecontext of those embodiments and examples, this disclosure extendsbeyond the specifically disclosed embodiments to other alternativeembodiments and/or other uses of the embodiments, as well as to certainmodifications and equivalents thereof. This disclosure expresslycontemplates that various features and aspects of the disclosedembodiments can be combined with, or substituted for, one another. Thus,the scope of this disclosure should not be limited by the particulardisclosed embodiments described above, but should be determined only bya fair reading of the claims that follow.

What is claimed is:
 1. A therapeutic ultrasound device for use during amedical procedure to cauterize tissue, the therapeutic ultrasound devicecomprising: an inner tube having a proximal end and a distal end,wherein the distal end of the inner tube comprises a first engagementportion configured to receive and secure a first moveable fastener; anouter tube having a proximal end and a distal end, wherein the distalend of the outer tube comprises a second engagement portion configuredto receive and secure a second moveable fastener, and wherein the outertube is disposed about the inner tube such that the second engagementportion is aligned with the first engagement portion; a tissue clampingassembly having a width less than about 15 millimeters and configured toapply a clamping force at a target site, wherein the tissue clampingassembly includes at least one transducer configured to providetherapeutic ultrasound, wherein the tissue clamping assembly comprises afirst jaw and a second jaw, and wherein a distal end of the tissueclamping assembly is configured to engage with the first engagementportion of the inner tube and the second engagement portion of the outertube; and a housing assembly secured to the proximal end of the innertube and the proximal end of the outer tube, wherein the housingassembly comprises a handle configured to actuate the inner tuberelative to the outer tube and close the tissue clamping assembly. 2.The therapeutic ultrasound device of claim 1, wherein the firstengagement portion of the inner tube is secured to the tissue clampingassembly with the first moveable fastener, and wherein the secondengagement portion of the outer tube is secured to the tissue clampingassembly with the second moveable fastener.
 3. The therapeuticultrasound device of claim 2, wherein the first jaw and the second jawof the tissue clamping assembly are configured to rotate about thesecond moveable fastener.
 4. The therapeutic ultrasound device of claim3, wherein actuating the handle in a first direction is configured tomove the inner tube and the attached first moveable fastener to separatethe first jaw and the second jaw, and wherein actuating the handle in asecond direction is configured to move the inner tube and the attachedfirst moveable fastener to bring the first jaw and the second jawadjacent to each other.
 5. The therapeutic ultrasound device of claim 1,wherein the outer tube comprises at least one of double hard stainlesssteel, aluminum, titanium, plastic, or carbon fiber.
 6. The therapeuticultrasound device of claim 1, wherein the inner tube comprises at leastone of double hard stainless steel, aluminum, titanium, plastic, orcarbon fiber.
 7. The therapeutic ultrasound device of claim 1, whereinthe first jaw and the second jaw are configured to apply any one ofabout 10 lbs., about 11 lbs., about 12 lbs., about 13 lbs. and about 14lbs.
 8. A therapeutic ultrasound device comprising: an inner tube havinga proximal end and a distal end; an outer tube having a proximal end anda distal end, wherein the outer tube is disposed about the inner tubesuch that the distal end of the inner tube and the distal end of theinner tube are aligned; an engagement assembly secured to the distal endof the inner tube and the distal end of the outer tube, and having awidth less than about 15 millimeters, wherein the engagement assembly isconfigured to apply an engagement force to a target and includes atleast one transducer configured to provide therapeutic ultrasounddirected to the target; and a housing assembly secured to the proximalend of the inner tube and the proximal end of the outer tube, whereinthe housing assembly comprises a handle configured to actuate the innertube relative to the outer tube, and wherein actuation of the inner tuberelative to the outer tube is configured to engage and disengage theengagement assembly.
 9. The therapeutic ultrasound device of claim 7,wherein the engagement assembly is configured to apply at least about 10pounds of engagement force to the target.
 10. The therapeutic ultrasounddevice of claim 7, wherein the engagement assembly comprises a first jawand a second jaw; wherein the first jaw and the second jaw are eachconfigured to engage with a moveable fastener to secure the first jaw tothe second jaw; and wherein at least one of the first jaw and the secondjaw is moveable.
 11. The therapeutic ultrasound device of claim 10,wherein the first jaw and the second jaw of the engagement assembly areconfigured to move relative to each other in a scissor-like movement.12. The therapeutic ultrasound device of claim 10, wherein the first jawand the second jaw of the engagement assembly are configured to moverelative to each other in parallel.
 13. The therapeutic ultrasounddevice of claim 10, wherein the distal end of the outer tube is engagedwith the moveable fastener to secure the first jaw and the second jaw ofthe engagement assembly, and wherein the inner tube is engaged with adistal end of the first jaw and the second jaw such that movement of theinner tube in a first direction separates the first jaw and the secondjaw and movement of the inner tube in a second direction brings thefirst jaw and the second jaw adjacent to each other.
 14. The therapeuticultrasound device of claim 7, wherein the engagement assembly engages atarget to apply engagement pressure and therapeutic ultrasound from theat least one transducer to seal the target.
 15. The therapeuticultrasound device of claim 7, wherein the engagement assembly engages atarget to apply engagement pressure and therapeutic ultrasound from theat least one transducer to cut the target.
 16. The therapeuticultrasound device of claim 7, wherein the outer tube comprises at leastone of double hard stainless steel, aluminum, titanium, plastic, andcarbon fiber.
 17. The therapeutic ultrasound device of claim 7, whereinthe inner tube comprises at least one of double hard stainless steel,aluminum, titanium, plastic, and carbon fiber.
 18. The therapeuticultrasound device of claim 7, wherein the engagement assembly comprisesat least one of stainless steel or ceramics.
 19. The therapeuticultrasound device of claim 7, wherein the transfer of force from thehousing assembly to the engagement assembly is about 20:1.
 20. Thetherapeutic ultrasound device of claim 7, wherein the engagementassembly has a width less than about 15 millimeters and greater thanabout 3 millimeters.
 21. A method of applying therapeutic ultrasound toa target tissue site, the method comprising: guiding a tissue engagementassembly to the target tissue site, the tissue engagement assemblycomprising at least one transducer configured to provide therapeuticultrasound to the tissue target site, wherein the tissue engagementassembly is secured to the distal end of an actuation device, andwherein the actuation device comprises an outer tube disposed within aninner tube, the outer tube configured to secure the tissue engagementassembly and the inner tube configured to move relative to the outertube to engage and disengage the tissue engagement assembly; actuatingthe inner tube in a first direction to engage the tissue engagementassembly with the target tissue site; applying engagement pressure tothe target tissue site with the tissue engagement assembly; providingtherapeutic ultrasound to the target tissue site via the at least onetransducer; and actuating the inner tube in a second direction todisengage the tissue engagement assembly from the target tissue site.22. The method of applying therapeutic ultrasound to a target tissuesite of claim 21, wherein the therapeutic ultrasound that is provided tothe target tissue site seals tissue at the target tissue site.
 23. Themethod of applying therapeutic ultrasound to a target tissue site ofclaim 21, wherein the therapeutic ultrasound that is provided to thetarget tissue site cuts tissue at the target tissue site.
 24. The methodof applying therapeutic ultrasound to a target tissue site of claim 21,wherein the tissue engagement assembly has a width less than about 15millimeters.
 25. The method of applying therapeutic ultrasound to atarget tissue site of claim 21, wherein the tissue engagement assemblyis configured to apply at least about 10 pounds of engagement force tothe target site.